S. Velasco

Effects of inulin and enzyme complex, individually or in combination, on growth performance, intestinal microflora, cecal fermentation characteristics, and jejunal histomorphology in broiler chickens fed a wheat- and barley-based diet

A study was undertaken to examine the effects of inulin, alone or in combination with enzyme complex (primarily xylanase and beta-glucanase), on growth performance, ileal and cecal microflora, cecal short-chain fatty acids, and d-lactic acid and jejunal histomorphology of broiler chickens fed a wheat- and barley-based diet from 7 to 35 d of age. A total of 240 seven-day-old male Cobb broilers were allocated to 1 of 6 treatments, with 8 replicate pens per treatment and 5 birds per pen. The experiment consisted of a 3x2 factorial arrangement of the treatments with 3 concentrations of inulin (0, 10, or 20 g/kg of diet) and 2 concentrations of enzyme complex (0 or 100 mg/kg of diet). At the end of the experiment, 8 birds per treatment (one from each pen) were randomly chosen and slaughtered. Birds fed inulin-containing diets exhibited significantly (P=0.043) improved final BW gain. Dietary inulin had a positive and significant (P<0.002 to 0.009) effect on bifidobacteria and lactobacilli counts in both ileal and cecal contents and, to an extent, also altered the fermentation patterns in the ceca, increasing the concentration of n-butyric and d-lactic acids and the n-butyric acid:acetic acid ratio. Inulin inclusion had no effect on villus height and crypt depth or microvillus length, width, and density in the jejunum. Enzyme supplementation of the control diet and inulin-containing diets had no effect on many of the variables studied and only resulted in a decrease in crypt depth and an increase in villus height:crypt depth ratio in the jejunum.

Effect of inulin supplementation and dietary fat source on performance, blood serum metabolites, liver lipids, abdominal fat deposition, and tissue fatty acid composition in broiler chickens

A study was conducted to evaluate the effect of adding inulin to diets containing 2 different types of fat as energy sources on performance, blood serum metabolites, liver lipids, and fatty acids of abdominal adipose tissue and breast and thigh meat. A total of 240 one-day-old female broiler chicks were randomly allocated into 1 of 6 treatments with 8 replicates per treatment and 5 chicks per pen. The experiment consisted of a 3 x 2 factorial arrangement of treatments including 3 concentrations of inulin (0, 5, and 10 g/kg of diet) and 2 types of fat [palm oil (PO) and sunflower oil (SO)] at an inclusion rate of 90 g/kg of diet. The experimental period lasted from 1 to 34 d. Dietary fat type did not affect BW gain but impaired feed conversion (P < 0.001) in birds fed the PO diets compared with birds fed the SO diets. The diets containing PO increased abdominal fat deposition and serum lipid and glucose concentrations. Triacylglycerol contents in liver were higher in the birds fed PO diets. Dietary fat type also modified fatty acids of abdominal and i.m. fat, resulting in a higher concentration of C16:0 and C18:1n-9 and a lower concentration of C18:2n-6 in the birds fed PO diets. The addition of inulin to diets modified (P = 0.017) BW gain quadratically without affecting feed conversion. Dietary inulin decreased the total lipid concentration in liver (P = 0.003) and that of triacylglycerols and very low density lipoprotein cholesterol (up to 31%) in blood serum compared with the control groups. The polyunsaturated fatty acid:saturated fatty acid ratio increased in abdominal and i.m. fat when inulin was included in the SO-containing diets. The results from the current study suggest that the addition of inulin to broiler diets has a beneficial effect on blood serum lipids by decreasing triacylglyceride concentrations The results also support the use of inulin to increase the capacity of SO for enhancing polyunsaturated fatty acid:saturated fatty acid ratio of i.m. fat in broilers.

Dietary Inulin Supplementation Modifies Significantly the Liver Transcriptomic Profile of Broiler Chickens

Inclusion of prebiotics in the diet is known to be advantageous, with positive influences both on health and growth. The current study investigated the differences in the hepatic transcriptome profiles between chickens supplemented with inulin (a storage carbohydrate found in many plants) and controls. Liver is a major metabolic organ and has been previously reported to be involved in the modification of the lipid metabolism in chickens fed with inulin. A nutrigenomic approach through the analysis of liver RNA hybridized to the Affymetrix GeneChip Chicken Genome Array identified 148 differentially expressed genes among both groups: 104 up-regulated (≥1.4-fold) and 44 down-regulated (≤0.6-fold). Quantitative real-time PCR analysis validated the microarray expression results for five out of seven genes tested. The functional annotation analyses revealed a number of genes, processes and pathways with putative involvement in chicken growth and performance, while reinforcing the immune status of animals, and fostering the production of long chain fatty acids in broilers supplemented with 5 g of inulin kg−1 diet. As far as we are aware, this is the first report of a microarray based gene expression study on the effect of dietary inulin supplementation, supporting further research on the use of this prebiotic on chicken diets as a useful alternative to antibiotics for improving performance and general immunity in poultry farming, along with a healthier meat lipid profile.

Nutrient content in the muscle and skin of fillets from farmed rainbow trout (Oncorhynchus mykiss)

The nutrient content in the muscle and edible skin parts of rainbow trout (Oncorhynchus mykiss) fillets, sampled at two growth stages, was evaluated. The average concentrations of protein and essential amino acids were higher in the muscle than in the skin. The chemical scores reached a value of 1.0 for the amino acids in the muscle and ranged from 0.40 (tryptophan) to 0.94 (threonine) in the skin. The average lipid content and the saturated fatty acids/polyunsaturated fatty acids and n-6/n-3 ratios were higher in the skin than in the muscle, whereas the proportion of docosahexaenoic acid (C22:6 n-3) was higher in the muscle. Significant differences were found for the essential minerals analysed, except for Cu. The concentrations of Na, K and Mg were higher and those of Ca, P, Fe, Mn and Zn were lower in the muscle than in the skin. Significant effects of the fish growth on the composition were detected.

Los prebióticos tipo inulina en alimentación aviar. I: características y efectos a nivel intestinal.

Tras la prohibicion por la Union Europea en 2006 del uso de los antibioticos promotores del crecimiento (APC) en alimentacion animal, los investigadores tuvieron que proponer alternativas a los productores de broilers para sustituir estos APC. Los prebioticos se definieron en 1995 como ingredientes alimentarios no digestibles que afectan de manera favorable al hospedador mediante la estimulacion del crecimiento de bacterias intestinales beneficiosas. Dentro de los diferentes prebioticos estudiados, la inulina ha destacado debido a los resultados alentadores obtenidos sobre diferentes parametros. En este trabajo se revisan, en primer lugar, los efectos de los prebioticos del tipo de la inulina sobre el intestino de los broilers, tanto a nivel macroscopico (longitud intestinal) como microscopico (tamano y densidad de vellosidades y microvellosidades), asi como sobre la microbiota intestinal. En segundo lugar, se hace una puesta al dia de la informacion publicada relativa a la influencia de la inclusion de inulina en la racion sobre la digestibilidad de los diferentes nutrientes.

Validation of an inductively coupled plasma-optical emission spectrometry method for the determination of major elements in farmed rainbow trout ( Oncorhynchus mykiss )

An inductively coupled plasma−optical emission spectrometry method was optimized and validated for the determination of major elements (Ca, K, Mg, Na and P) in cultivated freshwater fish (rainbow trout Oncorhynchus mykiss). The method was validated by analysis of a Certified Reference Material, consisting in a frozen tissue homogenate from lake trout (Salvelinus namaycush namaycush). The linearity of this method was very good, as evidenced by the coefficients of correlation (r) for calibration graphs that were higher than 0.9999 in all cases and by linearity test (response factor <5% and relative calibration graph slope <2%). Accuracy, expressed as relative recovery (%) in comparison with certified concentration ranged from 100 to 109%, and precision, expressed as residual standard deviation (%) ranged from 1.2 to 6.5% (repeatability) and from 1.0 to 9.6% (reproducibility). The limit of quantification ranged from 4 ng/mL (Ca and Mg) to 203 ng/mL (P). The optimized method was applied to major element determination in skin and muscle samples from rainbow trout fillets.